1. Field of the Invention
This invention relates to the prevention of loss of fluid from a container to which a closure cap is improperly applied or not applied at all, and preferably is used in conjunction with pressurized oil tanks of engines for jet aircraft. More particularly, this invention relates to a simple method and apparatus for converting a container that is subject to loss of fluid when a closure cap is either missing or misapplied to a filler spout into a container that is essentially free of spillage even when its closure cap is missing.
2. Technical Problems and the Prior Art
During flight, loss of oil has been a vexing problem for jet engines. One of the main reasons for this oil loss is the failure to close the closure cap for an oil tank properly after the tank has been filled with oil in preparation for a flight. The extent of oil loss is increased because most jet engines for aircraft use pressurized oil tanks. If loss of oil due to failure to close the oil tank properly is sufficient, it may require early termination of a flight to the annoyance of passengers. While other sources of oil loss exist, the one most susceptible of correction is the inadvertent carelessness of ground crew personnel to close the closure cap properly.
Several patents have been issued directed to containers having structure constructed and arranged to solve the aforesaid problem. However, most aircraft presently in service are provided with containers that are subject to leakage or spillage when the closure caps are improperly closed. It is an expensive and impractical undertaking to replace a container subject to loss of fluid when its closure cap is improperly closed by substituting one provided with means to prevent spillage or leakage even when uncapped. Prior to this invention, aircraft provided with prior art closure cap structures that require tight closing of the closure caps after filling have still been subject to the problem of spillage unless they were subjected to the large cost of replacing or rebuilding such storage tanks.
U.S. Pat. No. 173,452 to Donovan (1876) and 198,501 to Volkman (1877) disclose gravity activated, one-way flap valves for use in stench traps for toilets. The flap valves open when the toilet is flushed and close by gravity to seal off upward flow of noxious gases.
British Pat. No. 365,960 to Sansom, et al (1931) discloses a valve 7 that is spaced inwardly from the outer end of a filler spout 4 for a motor vehicle. The valve is spring loaded to open when a fluid dispensing nozzle is inserted through the valve opening at the inner end of the filer spout and to move upwardly to close the valve opening when the fluid dispensing nozzle is withdrawn.
U.S. Pat. No. 3,903,943 to Vest (1975) provides a supply tank with a self-closing adapter 21 that is forced open at its inner end by insertion of a fuel dispensing nozzle 14 therethrough and withdrawal of nozzle 14 allows adapter 21 to close in inwardly spaced relation to the entrance of filler spout 11. The latter is normally sealed by a closure cap 19. The self-closing adapter 21 prevents spillage from the supply tank even without a properly applied closure cap.
U.S. Pat. No. 4,135,562 to Martineau, et al. (1979) discloses a filling and venting device for a fuel tank. The device has a valve 16 that is spring loaded to be closed in spaced relation to the opening of the device. A closure cap 6 closes the opening. Whenever inward flow of fuel is stopped, valve 16 prevents outward flow of fuel even if closure cap 6 is not applied.
U.S. Pat. No. 4,501,374 to Robertson (1985) discloses a hazardous fluids tank having a check valve which includes a grommet 16 and a flap check valve 18. The latter extends inwardly into the tank interior to prevent reverse flow of the fluids out of the tank in case its filler pipe 20 or closure cap 21 is removed.